Section 3.2 Volcanic Activity

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Vocabulary

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Magma chamber: a pocket beneath the volcano that collects magma

Pipe: a long tube in the ground that connects the magma chamber to the crust

Vent: an opening where molten rock and gas leave the volcano

Lava Flow: the area covered in lava as it leaves the vent

Crater: a bowl-shaped area that may form at the top of a volcano

Silica: a material that is formed by the elements oxygen and silicon

Pahoehoe: a type of lava that flows quickly

Aa: a type of lava that is cooler and moves slowly

Pyroclastic flow: occurs when an explosive eruption hurls out ash, bombs, and more

Active: a volcano that is still able to erupt is an active volcano

Dormant: a sleeping volcano, would not erupt for a while

Extinct: a dead volcano, unlikely to erupt

Hot Spring: forms when groundwater heated by a nearby body of magma rises to the surface and collects in a natural pool

Geyser: a fountain of water and steam that erupts from the ground

Geothermal energy: water heated by magma can provide a clean and reliable energy source

Outline

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How Magma Reaches Earth's Surface

• magma rises
• a volcano erupts
  • under tremendous pressure

Inside a Volcano

• magma chamber
• pipe
• vent
• lava flow
• crater

Characteristics of Magma

• Silica

Types of Volcanic Eruptions

• quiet eruptions
  • Pahoehoe
  • aa
• explosive eruptions
  • pyroclastic flow

Stages of a Volcano

• active volcano
• dormant volcano
• extinct volcano

Other Types of Volcanic Activity

• hot spring
• geyser
• geothermal energy